In addition to the defeat, Napoli have also been docked one point for not attending the fixture.
After midfielders Piotr Zielinski and Eljif Elmas tested positive for COVID-19 earlier this month, Gennaro Gattuso's team remained in isolation on the instruction of local health authorities in Campania.
The Serie A disciplinary commission ruled that, despite the two positive cases, Napoli failed to follow the league's coronavirus protocol. The protocol, which adheres to UEFA's guidelines, dictates that matches can be played as long as the affected team is able to field 13 healthy players, including a goalkeeper.
Serie A noted at the time of Napoli's no-show that other games had already gone ahead despite the clubs involved registering positive COVID-19 tests.
The league added that the conditions for postponement didn't apply in Napoli's case.
Juventus, along with the referees, arrived at the Allianz Stadium as planned on Oct. 4. The match was eventually abandoned 45 minutes after the scheduled kickoff time.
Juventus president Andrea Agnelli said Napoli counterpart Aurelio De Laurentiis asked him to postpone the contest, to which he replied "there are regulations to be respected."
"We have protocols that are very clear," said Agnelli.
"The protocol was studied by the Federation with the government," he continued. "It is a living document, the important thing is to have the spirit of sporting honesty, the cases will be dealt with and resolved from time to time."